Skip to main content

Full text of "Rapid Population Growth Consequences And Policy Implications"

See other formats

In another British study, Grant (37) followed the growth of 1,310 children living in a London County Council housing estate, most of whom were measured at or near their sixth, tenth, twelfth, and fourteenth birthdays. Her findings parallel those reviewed above, but she also used her data to clarify several points. Taking advantage of the longitudinal nature of her material she showed that the differences in average (mean) measurements (at various ages) associated with family size are, in fact, the product of continuing slower rates of growth in children from larger families. The mean increments over a period of time, for example, between the sixth and tenth birthdays are shown in Table 6, are less in the children from larger families.
Gain in Height between Sixth and Tenth Birthdays, by Family Size, London, 1953-1960
Number of                                                            Height Gain between Sixth and
Children in                                                                  Tenth Birthdays (cm.)
Family                                                     Boys                                                   Girls
1                                                                        23.3                                                    23.6
2                                                                        23.0                                                    23.4
3                                                                        22.9                                                    23.3
4                                                                        22.4                                                    22.1
5  or more                                                    22.1                                                    22.6
Source: Grant (37).
She also examined the interaction between family size and birth rank and produced some thought-provoking results. One example is shown in Figure 7 which was constructed from her data. The figure shows only heights in boys, but the same trends are evident in her data for height and weight in both sexes. In order to examine this phenomenon further, she assigned a plus or minus "developmental level" (DL) based on the difference in centimeters between the measured height of a child and the expected average height for his age, using London data for comparison. The DL was assigned on the basis of heights obtained at or near age 8, to avoid growth variations produced by pubertal growth, and it allowed her to compare both boys and girls. She then compared the first and second child in consecutive pairs of children in families of different sizes and obtained the data shown in Table 7. As she noted, "the later-born child of any consecutive pair within a family tended to be taller than the preceding one." In her discussion, she noted:
. . . that the smaller size of children in larger families is common to all of them and that the first-born does not achieve the height and weight of